First Republic & Civil War — the Calabar front (1960–1970) — Cross River State

Calabar invasion, 18 October 1967 — the 3rd Marine Commando Division under Col. (later Gen.) Benjamin Adekunle ("the Black Scorpion") amphibiously assaults Calabar from MV *Lokoja* and *Kano* with Naval gunfire support; Biafran forces under Col. Ogbu Ogi Kalu collapse within 24 hours; c. 2,000 federal and Biafran casualties in the city, with documented massacres at the Henshaw Town wharf and the Old Calabar Cemetery (per Achebe, *There Was a Country*, and ICRC reports).
Recapture and occupation, 1967–1970 — Calabar serves as the headquarters of the federal 3 Marine Commando for the rest of the war; refugees from Annang/Ibibio country swell the city.
Asaba-style killings at Oron and Itu (1968–1969) — disputed; documented in some Igbo-secession sources, contested in others.